I must apologize yet again for how late these commentaries are coming. RL has been sapping a lot of my energy and I end up wasting a lot of time where I should be productive.
Positives first up: I'm liking the personality that's showing through on all three of these characters. Calvinia is a good offset for Laermont, and Simonus is the perfect weasel to be extorting information from. As always, I'd like to see more descriptiveness, setting the mood and tone, informing nuance through body language, but it's not that these things are absent -- I just encourage you to add more. It's only an interrogation scene so you have limited tools to work with, but in a noir themed story, an interrogation can be stylized and dramatized to heighten its importance.
My first complaints are plot-related, and tie back to my feedback on your earlier piece mentioning Guadriar:
One other detail: you wrote Guadriar the Red, but given the context, it would be another member of the NIN, Artemis Culpeper, who would meet with Mercuti. Guadriar is the man in charge of the NIN -- which isn't the entire Nefastus, but a significant group within it -- and he's unlikely to leave the safety of Lupanar. Artemis handles brokering information to and from industrial leaders in Terminus, and is the one with ties to TorBru. The nature of their business would also be information or misinformation, not protection.
However, rather than retconning the two chapters to feature Culpeper, I propose that Simonus has been knowingly or unknowingly fed the lines about Guadriar in order to lure Laermont into a meeting with the man. If you'd like to do that meeting as a collab, I'd actually enjoy writing something in a bit of a different style. Put my money where my mouth is, so to speak.
Summed up, though, this was a short but fun read. Keep it coming and keep on refining your unique style.